Clutch for refrigerating apparatus



Aug. 11, 1936. Q GRAHAM 2,050,836

CLUTCH FOR REFRIGERATING APPARATUS Filed March 28, 1932 2 Sheets-Sheet 1A INVENTOR.

ATTORNEY.

Aug. 11, 1936. F. o. GRAHAM CLUTCH FOR REFRIGERATING APPARATUS FiledMarch 28, 1932 2 Sheets-Sheet 2 INVENTOR.

W N? 0. GRQHQ R ATTORNEY,

Patented Aug. 11, 1936 CLUTCH FOR REFRIGERATING APPARATUS Frank 0.Graham, Detroit, Mich, assignor to Kelvinator Corporation, Detroit,Mich, a cornotation of Michigan Application March 28, 1932, Serial No.601,506

4 Claims.

This invention relates to refrigerating apparatus and particularly toapparatus used for operating refrigerating apparatus.

An object of the present invention consists in providing a new andoriginal type of hydraulic regulator which lends itself to strong anddurable construction and which is simple and inexpensive to manufacture.

Another object is to provide animproved fluid pressure controlledmechanism for operating a work device at a substantially constantpredetermined rate of speed at which the work device is designed tooperate from a source of power which develops a rate of speed other thanthe rate of speed at which the work device is designed to operate.

A further object is to provide an improved hydraulic speed regulator,the operation of which is controlled by mechanism located entirelywithin the interior of said regulator so that no moving parts, with thepossible exception of the driving member, are located on the outersurfaces of the regulator.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings, wherein a preferred form of the present invention is clearlyshown.

In the drawings:

Fig. 1 is a view indicating diagrammatically a refrigerating system inconnection with a motor vehicle constructed in accordance with myinvention,

Fig. 2 is an enlarged view of a portion of the refrigerating systemremoved from the vehicle,

Fig. 3 is a view in elevation of the hydraulic speed regulator embodyingfeatures of the invention,

Fig. 4 is an enlarged vertical view in cross section of the regulatorand showing a supporting bearing box for the regulator, partly in crosssection and partly in elevation,

Fig. 5 is a view in cross section of the regulator, taken along the line5--5 of Fig. 4,

Fig. 6 is a fragmentary view in cross section of the regulator, takenalong the line $6 of Fig. 5,

Fig. 7 is a fragmentary view in cross section, taken along the line 1-1of Fig. 5, and

Fig. 8 is a view in cross section of a modified form of speed regulatorembodying features of my invention.

Referring to the drawings, the numeral indicates any suitable motorvehicle operated by motor 2| and includes the usual transmission 22. Thetruck is provided with a body portion divided into an insulatedrefrigerating compartment and a machinery compartment iii. The vehiclecarries a refrigerating system diagrammatically represented as includinga cooling or evaporating unit 32 located in the refrigerating 5compartment, and in the machinery compartment there is located acondensing unit 35 which is adapted to be operated by the motor 2i at asubstantially constant speed through the medium of a hydraulic speedregulator 37 as is herein- 10 after more fully described.

Referring more in detail to the drawings, the condensing unit 35 may beof any suitable type and as herein shown includes a compressor 38,liquid refrigerant receiver 39, condenser 46, and 1 electric motor 4!connected with the compressor 38 by belt 63. These parts are all mountedon an angle iron base which is supported by the chassis frame of thevehicle in compartment 3!. The compressor withdraws refrigerant vapor 20from the evaporator through a vapor conduit 67, compresses the vapor andthrough a conduit it delivers it to the condenser wherein it isliquefled and from which it is delivered through conduit 50 to thereceiver 39. Liquid refrigerant is 25 supplied to the evaporator fromthe receiver through a liquid supply conduit 52 under the control of anexpansion valve 56.

The machine compartment 3| is provided with a louvred front panel 33 andan opening in the 30 lowermost part thereof to permit the freecirculation of air therethrough. Such a circulation of air is utilizedfor cooling the condenser and to remove heat generated in compartment3!. For the purpose of creating a sufilcient flow of air 5 a fan 55 isprovided. The fan 55 is mounted on the armature shaft of the motor M.This fan is arranged to be operated by the motordl when the motor isoperating the compressor and is adapted to be operated by the compressorthrough belt 63 when the compressor is being operated by the vehiclemotor. During periods when the vehicle motor is employed for operatingthe compressor, the armature and its shaft of the motor 4| rotate merelyto drive the fan 55.

During periods when the compressor is operated by the motor of thevehicle, the motor M is unnecessary. However, in the event it is desiredto refrigerate the compartment 30, when the vehicle motor is not inoperation, for instance, over- 50 night when the vehicle is in thegarage, the motor M may be connected to the usual electric source ofsupply in the garage for operating the compressor 38.

The refrigerating system is preferably inter- 55 substantially constanttemperatures in the compartment 38. Any suitable means such as athermostatically controlled electric switch (not shown) responsive tochanges in temperature within the compartment 38 may be used to closeand open the motor circuit for controlling the on and off phases of therefrigerating cycle of the system when the motive power is the motor Asshown in the drawings, the hydraulic regulator 31 is connected to thevehicle motor by a power take off shaft 68 which is adapted to be movedinto and out of engagement with the transmission 22 by lever 62 asdesired. A belt 64 is used to drive the compressor by the regulator 31.The regulator is located on the exterior of the truck and the regulatorend of the shaft 68 is supported in a suitable bearing box I8 providedwith roller bearings II. A fltting I2 is provided for permittingsuitable lubricant to be supplied to the interior of the box I8. Thisbox not only provides an adequate support for the regulator 31 but alsopermits the shaft 68 to rotate with only a negligible amount offriction. The bearing box I8 is mounted on a supporting frame I3 carriedby brackets I4 depending from the chassis frame of the vehicle.

In order to provide proper refrigeration within the compartment 38 whenthe compressor is operated by the vehicle motor, any suitable signaldevice such as a thermostatically controlled light or thermometer (notshown) responsive to changes in temperatures in compartment 38 may belocated on the dash board or other conspicuous place on the vehicle tonotify the operator of the vehicle when to engage and disengage theshaft 68 with the transmission.

As shown in Figs. 3, 4, 5, 6, and 7 the regulator comprises in general afluid-tight rotatable housing I5 formed preferably by three castingmembers, namely, an outer member 11 having a plurality of radial heatdissipating fins I8 formed integrally therewith, a central member I9having annular heat dissipating fins 88 formed integrally therewith, anda third member 8| which is provided with a V shaped pulley means 82formed integrally therewith on its outer periphery for receiving belt64. These three members are suitably secured together by screws 83 andbetween the joints of said members there are provided suitable gasketmembers 84.

Within the housing I5 there are provided two compartments, namely, a lowpressure compartment 85 and a high pressure compartment 86 both of whichare adapted to be filled with fluid, preferably non-compressible fluid,such as lubrieating oil. These compartments are separated from oneanother by partition means including inwardly extending portions 88 and89 of the casting I9, a sun gear 92 secured to shaft 68 by key 94 forrotation with said shaft and a planetary gear 95 which is secured to ashaft 91 by a key 98. The inwardly extending portions 88 and 89 ofcasting I9 are recessed as at I88 and I M, which recesses providesubstantially semi-cylindrical sheathings for gears 95 and 92respectively. A central web I8, best shown in Fig. 7, is provided forstrengthening the portions 88 and 89. Openings I81, I88, I69, H8, and,III are provided in web I84 for establishing communication betweenopposite sides of the web. The gears 92 and 95 are arranged for rotationwithin the opening I89 and the recesses I68 and NI and constitute thefluid pumping means for delivering fluid from mittently operated and isadapted to maintain,

the low to the high pressure compartment for effecting rotation of theregulator to drive the compressor as is hereinafter described.

In order to provide means for controlling the speed of the housing 15, Ihave provided a by- 5 pass valve I28. The valve I28 is adapted tocontrol the pressures and the flow of fluid in the housing I5 duringnormal operation of the refrigerating system and the regulator 31 tothereby I provide for the operation of the compressor at 10 asubstantially constant predetermined rate of speed after the speed ofthe vehicle motor attains a predetermined value as is hereinafter morefully described. This valve is of the piston type, radially disposed andarranged to slide in a bore 15 I22 provided in the inwardly extendingportion 89 of casting I9. The valve I28 controls passages I25 and I26between compartments 85 and 86. This valve is arranged to open bycentrifugal force against the action of a coiled spring I38 20 whichsurrounds a reduced portion I3I of the valve body I33 within bore I22.The spring applies its force on the valve body on its one end and abutsa removable plug I34 on the other end.

In order to prevent a dash-pot action in the bore 25 I22, I haveprovided the valve I28 with a longitudinal bore I35. An annular grooveI3! is provided on the body portion I33 of valve I 28 to provide a spacebetween the valve body and the walls of the bore I22 for receiving dirtparticles to pre- 30 vent binding of the valve. To provide the valveproper I28, the body portion I33 is drilled as at I48 and is providedwith four longitudinal equally spaced slots I II. Thus when the valve ismoved to open position, the flow of fluid from the high 35 pressurecompartment to the low pressure com partment may freely pass frompassage I25 to passage I26 through the slots IdI of valve I20. Thisprevents fluid pressures in compartment 86 from affecting operation ofthe valve and in order to further insure against pressures affectingoperation of the valve, the inwardly extending portion 89,is providedwith a recess I58 in communication with the passage I25 to thus providefor completely surrounding a portion of the valve with fluid in the highpressure compartment. When the valve is open, the fluid from the highpressure compartment flows to the low pressure compartment through thevalve, not only from the passage I25 but also from the recess I58. Thusit will be noted that the operation of the valve is entirely unaffectedby pressures within the housing. This prevents jamming of the valve. Inorder to provide a valve which is operable by centrifugal force and toarrange its actuating 5 forces which are influenced by centrifugal forceentirely within the housing, I have constructed the valve body ofmaterial such, for example, as steel having sufficient weight so as tobe responsive to centrifugal force for opening the valve.

In order to provide a regulator which will operate smoothly, I havejournaled the shaft 91 in anti-friction ball bearing members I 52 andI54 and have mounted the housing 15 on shaft 68 by means ofanti-friction ball bearing members 6:;

tween the sealing member and shoulder I 86. The diaphragm is held inplace by an outer cover member III secured to casting 8i by screws I12.This cover plate carries an annular felt member I15 adapted to engagethe shaft 68 for preventing dust and the like from coming into contactwith the sealing parts. Bearing member I56 is mounted on the reducedportion I15 of shaft 88. The reduced portion I15 and bearing I56 aredisposed within a recessed chamber III provided in casting 18. Therecessed chamber III is closed by a removable cover plate I18 secured tocasting I8 by screws I88. Suitable spacing means are provided formaintaining the bearings I56 and I58 in proper position. This spacingmeans comprises collars I82, I88, and I84. Collar I82 is placed betweenbearing I56 and gear 92, the collar I83 between gear 92 and bearing I58,and the collar I84 is placed between bearing I58 and a spring retainingmeans I86. These parts are all suitably locked in position by means ofnut l8? threaded on the end of shaft 88. A lock washer I88 is providedfor preventing accidental removal of nut I81 during operation of theregulator.

Preferably the chambers I62 and I'll are filled with oil to provideadequate lubrication for the bearings I56 and I58. Suitable removableplugs I98 are provided for admitting oil to the interior of the housing.The oil admitted to the interior of the housing enters the compartments85 and 88 and by seepage between casting I8 andthe gear 92 flows intochamber Ill and by seepage between casting 8| and gear 92 flows throughan annular passageway I92 in casting 8i into chamber I52. When thistakes place, some of the oil will also flow to the bearing members I52and I58 to provide adequate lubrication therefor. Thus it will beapparent that the compartments 85 and 85 and the chambers I62 and I'llare completely filled with oil and that this oil provides adequatelubrication at all times for all of the bearing members of theregulator.

The operation of the device is as follows: Assuming that the vehiclemotor 2i is in operation and that the lever 62 has been moved to placethe shaft 88 in engagement with the transmission, the gear 92 in housingI5 will be operated by shaft 88 in a counter-clockwise direction asshown by the arrow in Fig. 5. This movement of gear 92 causes rotationof gear 95 in a clockwise direction as shown by the arrow in Fig. 5.Upon rotation of the gears, some of the oil in compartment 85 will bedelivered to compartment 86 between the teeth of the gears and thesheathings I88 and MI. In order to prevent the possibility of moving theshafts 60 and 97 out of proper alignment in attempting to compress oilpocketed between the teeth of the gears, there is provided a cavity I98for receiving fluid ejected by meshing of the gears. As the fluid isgradually delivered to compartment 86 or the high pressure compartmentfrom compartment 85 or low pressure compartment by gears 92 and 95, thefluid pressure in the high pressure compartment gradually increases.When the pressure in the high pressure compartment is increased to sucha point so as to overcome the resistance to rotation offered by thehousing I5 in tending to drive the compressor 38, the pressure incompartment 86 will lock the gears in position and the entire regulatorwill rotate to drive the compressor.

During periods when the pressure within the compartment 86 is suflicientto lock the gears to rotate the housing I5, said housing rotates at thesame speed of the driving shaft 68. When the speed of the housingattains a predetermined value. for instance the rate of speed at whichthe compressor is designed to operate, the centrifugaily operated valveis moved toward the outer periphery of the housing suililciently to openthe valve to permit some fluid to be bypassed from the high to the lowpressure compartment. This causes the gears 82 and 85 to resumerotation. When this takes place, a certain amount of slipping or lostmotion takes place between the rotatable housing and the shaft 68.Thereafter, any slight increase in the rate of movement of the housingwill cause the valve I 28 to open farther to thereby increase the amountof fluid being by-passed. This allows a greater amount of slipping orlost motion to take place between the housing and the shaft 88. Byresuming the rotation of the gears, said pressures would be increased inthe compartment 88 if it were not for the by-pass valve I28 which, aspreviously stated herein, is responsive to the speed of the housingandallows fluid to be bypassed in varying proportions. That is, any slightincrease in pressure within the compart ment 88 which would tend toincrease rotation of the housing I5 would cause the valve to openfarther and allow more fluid to be by-passed to immediately reduce thepressure acting on the gears in the compartment 88 to thus permit thegears to rotate to effect a hydraulic frictional connection between thehousing and the shaft 68. The weight of the valve body portion 888 andthe tension of the spring I38 have been designed to permit the valve toby-pass sufiicient fluid so as to maintain the movement of the housingI5 substantially constant when the speed of the housing attains apredetermined value irrespective of the variations in speed of thedriving shaft 88 after the shaft 68 is running above a predeterminedrate.

As the speed of the motor and consequently the speed of the housinggradually decreases, the spring I38 gradually overcomes the outwardmovement of the centrifugally operated valve and tends to close thevalve. When the speed of the housing falls below a certain value, thespring closes the valve. Thus it will be noted that the .centrifugallyoperated valve determines the flow of fluid within the compartments 85and 88 to thereby determine the speed of the housing I5.

The hydraulic regulator 31 is readily adaptable for use in driving othercompressors which are designed to operate at greater or less speeds bysimply substituting a stronger or weaker spring for spring I88 or byfilling the housing with a fluid of suitable viscosity. 1 i

Fig. 8 shows a modified form of regulator designated I98. This regulatorcomprises a rotatable housing 288 in which there is provided a highpressure compartment 282 and a low pressure compartment 288, a sun gear285 secured to shaft 88, a planetary gear 288 and a by-pass valve 281all of which correspond to like parts of the regulator 8i and operate ina like manner. This regulator however. is provided with means forpreventing rotation of shaft 68 when the motor M is operating thecompressor. This means comprises a valve 2i8 adapted to be held inclosed position by spring 2 when the gear 95 is rotating in a clocfiwisedirection and also when gear 95 is locked to gear 92 by fluid within thehousing. However, in the event the gear 85 is rotated in thecounter-clockwise direction, the valve 2I8 is arranged to be opened by aslight increase in pressure in the compartment 204. This slight increasein pressure takes place due to the rotation of gear 05 in acounter-clockwise direction, the compartment 204 then becoming the highpressure compartment and the compartment 202 becoming the low pressurecompartment. When the valve H0 is in an open position, fluid freelycirculates from one compartment to another through valve 2l0 and passage2I5 to prevent any pressures from building up in compartments 202 and204. Among the times when gear 95 would be rotated in acounter-clockwise direction is when the motor 4| is driving thecompressor. At this time the housing 15 would be rotated by belt 54.This causes gear 95 to rotate about gear 92. This rotation builds up aslight pressure in compartment 204 which opens valve 200 and if it werenot for valve 200 the pressure in compartment 204 would soon increasesufllciently to lock gears 95 and 92 and thus cause rotation on shaft60. This not only prevents a waste of power utilized in driving shaft 60but also avoids the danger of damage to the transmission 22 which wouldbe likely to take place by rotation of shaft when the motor 2| isinoperative, and in the event the shaft 50 was inadvertently left inengagement with the transmission.

A valve 220 is also shown in Fig. 8. Valve 220 is normally held closedby spring 22 I. This valve is responsive to abnormally high pressureswithin the compartment 202 for permitting the free circulation of fluidthrough passage 222 between the compartments 202 and 204 in the eventthe pressures in the compartment 202 become dangerously high. Abnormallyhigh pressures within the compartment 202 may take place as a result ofabnormal conditions within the refrigerating system such as sticking ofthe compressor. By failure. of the compressor to operate, the housing 15would remain stationary and the gears 92 and 95 would continue to rotateand build up the pressure in compartment 202 until it would becomedangerously high if it were not for valve 220. Another condition causingabnormally high pressures in' compartment 202 would be the suddenengagement of shaft 00 with transmission 22 when motor 2| is operatingat a high rate of speed. I

In the regulator I99 the valve 201 corresponds to and operates in a likemanner as does valve 130. As shown in Fig. 8 a spring I32 is provided toresist the outward movement of the valve I30. This spring abuts thevalve body on one end and on the other end abuts a shoulder I34 of anadjustable member I35 which is screw threaded into a removable plug I31.This arrangement permits adjustment of the tension of spring I32 tothereby render the regulator readily adaptable for use in operatingcompressors designed to operate at different speeds. 4

From the foregoing it will be apparent that I have provided forrefrigerating a motor vehicle by a refrigerating apparatus of thecompression type and that I have arranged for operating the compressorof said refrigerating apparatus at a substantially constant speed by themotor of the vehicle. It will also be noted that the compressor isoperated by the vehicle motor through the medium of a hydraulic speedregulator, the hydraulic action of which becomes gradually effective toinitially operate the compressor and that means are provided formaintaining said hydraulic action substantially constant after the speedof the regulator attains a certain value to thereby control the rate ofmovement of the compressor. This arrangement provides for thetransmission of power to the compressor from the vehicle motor in asmooth and nonfluctuating manner.

It will also be apparent from the foregoing that I have provided ahydraulic regulator for operating a compressor at a substantiallyconstant speed by power received from the vehicle motor and that I havearranged the control mechanism of the regulator and its operating partsentirely within a fluid tight housing. This arrangement is advantageousin that it avoids any possibility of leakageof fluid from the housingand also eliminates the possibility of dirt particles and the like frominterfering with the proper operation of the regulator. This latterarrangement is particularly advantageous where the regulator is locatedon the exterior of the vehicle.

Although a preferred embodiment of my invention is herein shown inconnection with a motor vehicle, it is to be understood that all typesof vehicles such for example as railway cars come within the scope ofthe invention and that it is immaterial whether the power for operatingthe refr'gerating apparatus is derived from the vehicle motor or frommotion of the vehicle.

Although only a preferred form of the invention has been illustrated,and that form described in detail, it will be apparent to those skilledin the art that various modifications may be made therein withoutdeparting from the spirit of the invention or from the scope of theappended claims.

What is claimed is as follows:

1. The combination with a variable speeddriving element of a rotatabledriven element including a housing, partition means dividing saidhousing into two compartments, said partition means including fluidpumping means for delivering fluid from one compartment to another,means providing a by-pass between said compartments, a radially disposedpiston type valve member arranged for movement in said partition meansfor opening said by-pass in accordance with increasing speed, and meansfor preventing a dash pot action during operation of said valve.

2. The combination with a variable speed driving elementof a rotatabledriven element in-, cluding a housing, partition means dividing saidhousing into two compartments, said partition means including fluidpumping means for delivering fluid from one compartment to another, saidpumping means including a sun gear actuated by said driving element anda planetary gear in mesh with said sun gear, means providing a by-passbetween said compartments, and a radially disposed piston type valvemember arranged for movement in said partition means for controllingsaid by-pass, said piston type valve being influenced by centrifugalforce for opening said valve after the speed of one of said elementsattains a predetermined value.

3. The combination with a variable speed driving element of a rotatabledriven element including a. housing, partition means dividing saidhousing into two compartments, said partition means including fluidpumping means for delivering fluid from one compartment to another, saidpumping means including a sun gear actuated by said driving element anda' planetar'y gear in mesh with said sun gear, means providing a by-passbetween said compartments, means responsive to pressure in said lowpressure compartment for opening said by-pass to prevent reverseoperation, and a radially disposed piston type valve member arranged forcontrolling said by-pass, said piston type valve being influenced bycentrifugal force for opening said valve after the speed of one of saidelements attains a predetermined value.

4. In a constant speed power transmitting system the combination of apair of power transmitting elements, hydraulic speed regulating meansoperatively connected between said elements comprising a pair of fluidenclosing chambers, fluid pumping means actuated by relative movementbetween said elements for pumping fluid from one of said chambers to theother, a

by-pass passage for discharging the pumped fluid, a radially slidablevalve piston of pressure balanced conformation in said passageway forby-passing the pumped fluid in accordance with the speed of one of saidelements and irrespective of its rate of acceleration orthe pressure ofthe fluid, and an aperture extending axially through said valve pistonto by-pass displacement fluid therethrough thereby providing quickresponse and eliminating dash-pot effects.

FRANK O. GRAHAM.

